#!/usr/bin/python
import sys
import os
import re

# unpack packages listed in file sys.argv[1], 
# unpacked folder name is basename of filename
# apply patch listed in file sys.argv[2]

if len(sys.argv)<3: raise Exception('Requires two arguments.')
pkglist=open(sys.argv[1],'r')
patchlist=open(sys.argv[2],'r')

os.chdir(os.path.dirname(os.path.abspath(sys.argv[0]))) # chdir to the directory where `unpack' stays

if not os.path.exists('tmp'): os.mkdir('tmp')

dirs=[] # directories to apply patch

# unpack
os.chdir('tmp')

for pkg in pkglist:
	pkg=pkg.strip()

	if not os.path.exists(pkg): raise Exception('Pkg not exists.', pkg)

	# get filename(*.tar.gz *.tar.bz2) from file_path(/srcpkg/*)
	filename=os.path.basename(pkg)

	# get basename from filename, and construct command(tar zxf/jxf)
	if re.search(r'\.tar\.gz$', filename):
		basename=re.search(r'(.+)\.tar\.gz$',filename).group(1)
		cmd='tar zxf %s'%pkg
	elif re.search(r'\.tar\.bz2$', filename):
		basename=re.search(r'(.+)\.tar\.bz2$',filename).group(1)
		cmd='tar jxf %s'%pkg
	else:
		raise Exception('Unsupported package format. ',pkg)

	# if not exist ../basename, then unpack
	if os.path.exists('../'+basename)==False:
		print cmd
		if os.system(cmd): raise Exception('Cannot unpack',pkg,cmd)
		if len(os.listdir('.'))>1: raise Exception('More than one dir unpacked.')
		if os.system('mv %s ../%s'%(os.listdir('.')[0],basename)):
			raise Exception('Cannot mv','mv %s ../%s'%(os.listdir('.')[0],basename))
	dirs.append(basename)
if len(dirs)==0: raise Exception('No pkg provided.')

os.chdir('..')
os.rmdir('tmp')

def match(L,s): # return the element match `s' in `L'
	ret=None
	for l in L:
		if re.search(s,l):
			if ret: raise Exception('more than one match.', L, s)
			ret=l
	if ret==None: raise Exception('no element matches.', L, s)
	return ret

# patch
order=[
('linux',''), 
]

patch=[] # contains basename of patches.
for p in patchlist:
	p=p.strip()
	if len(p)>0: patch.append(os.path.basename(p.strip()))
	if re.search('\.patch$',p)==None: raise Exception(patchlist.name+'format error.')
	if not os.path.exists(p): raise Exception('Patch not exists.', p)
if len(patch)==0: raise Exception('No patch provided in '+patchlist.name)

for (s1,s2) in order:
	s1=match(dirs, s1) # dir name
	s2=match(patch, '%s.+%s'%(s1,s2) ) # patch basename
	patchpath='/srcpkg/'+s2 # patch file path
	os.chdir(s1)
	if not os.path.exists(s2):
		patchcmd='patch --silent -Np1 -i '+patchpath
		print patchcmd
		if os.system(patchcmd): raise Exception('Cannot patch', patchcmd)
		if os.system('cp %s .'%patchpath): raise Exception('Cannot cp. Please remove the whole dir.', 'cp %s .'%patchpath)
	os.chdir('..')
